Although my child is not autistic, he is still classified somewhere on the Spectrum, and I try to keep on top of the Autism news. So when I received the new issue of Seed, I went right to the article by Simon Baron-Cohen, titled, "When Two Minds Think Alike".
It's an interesting theory he posits. With the rise in cases of diagnosed autism from 4.5 cases per 10,000 live births in 1999 to 40 cases per 10,000 live births in 2005, many people are trying to figure out what the reason for the increase is. Baron-Cohen's theory is that assortative mating has a key role in autism's increased prevalence. Basically, assortative mating means that humans (or animals) tend to seek out and have children with others who share common traits. In this case the common trait would be systemizing. Baron-Cohen postulates that the increase in economic opportunities for women, primarily in the computer fields, have brought men and women who are strong systemizers into close proximity, and it is the combination of having two parents who favor these traits that increase the likelihood of having an autistic child. He contends that the behavior of autistic individuals is simply the same systemizing behavior of their parents writ large.
Baron-Cohen's theory is testable and it is in the testing that we will see if it it holds any water. The testable part of the theory goes like this:
IF systemizing is a male-oriented trait
THEN both the mothers and fathers of autistic children should show signs of this trait, along with more male-oriented interests in general
AND IF the "maleness" of this trait corresponds to testosterone levels, specifically higher prenatal testosterone levels
THEN mothers of autistic children may also be more likely to suffer from testosterone-linked medical conditions.
I am interested to know how Baron-Cohen's theory holds up in testing, although it will certainly be awhile before anyone knows the answer to that. Assortative mating is a theory that has been around for a long time and has been used to explain anomalies such as why there are more gifted people than can be reasonably expected if the population followed the "bell curve". (Answer: Gifted people tend to marry other gifted people and their children also tend to be gifted, thus the number of gifted people in the population is greater than it would be if people married and reproduced in a more "random" fashion.)
Although Baron-Cohen's theory is receiving a lot of notice right now, the idea that assortative mating could be a factor in the prevalence of autism is not a brand-new idea. In the March-April 2003 issue of Brain Work, Maia Szalavitz highlights Baron-Cohen's theory and discusses the “systemizing” aspect more thoroughly. The theory is that autism may be similar to sickle cell anemia in that it is caused by a gene which governs the ability to understand, organize and manipulate complex, “rule-governed areas of knowledge such as computer languages and mathmatics, which tend to predominate in males.” As in sickle cell anemia, where one copy of the gene provides protection from malaria, while two copies result in the disease, the contention is that one copy of the “autism gene” produces enhanced systemizing skills, while two copies can result in autism.
Another even more in-depth look at this theory can be found at Edge: The Third Culture. Here Baron-Cohen discusses in detail how he has gone about testing his theory including the difficulties involved in testing 24 hour old infants in the hospital. The responses to this article highlight among other things, the problems that occur when you label anything "male" vs. "female". Regardless of any validity that may be inherent in the theory, the use of a gender or sex-based "trait" is going to push buttons and cloud the debate.
This theory is as interesting to me as any theory on the cause of autism. Back in the late '80's and early '90's there was much speculation about a cluster of autistic children born to parents who had either worked in the Foster Grant factory in Leominster, MA or had grown up in the immediate vicinity of the factory. There were discussions of the toxic fumes being the cause of the autism, but also of possible genetic damage to the parents of these children. Is it possible that there is a solitary cause of autism? My gut feeling is no. Just as the children on the spectrum range in ability, so too, I think we shall see, the causes range, and sometime converge with devastating effects. I do think that we are getting closer to identifying some of these causes, and only hope that their discovery will result in hope and help for the children and their families.
